faqs for DPs

DPs stuff

INDEX (frame mode)
filters. Animation curtsey of Artem Visual Effects
Depth of field tables curtsey of Cooke Optics

http://www.cinematography.net/default.htm Good tech info site

UK Sun tables

Maximum height of the sun at noon (London: 51deg N)

Jan

Feb

Mar

Apr

May

Jun

Jul

Aug

Sep

Oct

Nov

Dec

19°

27°

36°

50°

59°

63°

61°

54°

43°

31°

22°

17°

Sunrise and Sunset positions (North or South of Due East/West):

Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
34°S	21°S	6°S	16°N	30°N	37°N	34°N	22°N	5°N	14°S	29°S	37°S

links: see sunPATH from Wide Screen Software US (818) 764-3639 for altitude/azimuth bearings for anywhere in the world on a specific day

Colour temperature tables:

Source (assume -10° K for each 1 volt drop in supply)	Kelvin	Mireds (1/Kelvin)
Domestic Tungsten	2900	345
Photographic incandescent or Halogen Tungsten	3200	312
Photoflood or 3200° source + 1/8 CTB	3400	294
3200° source + ¼ CTB	3600	278
3200° source + ½ CTB	4100	245
3200° source + full CTB	5550	182
Dawn or Dusk	2000	500
Sunrise + 1 hour	3500	285
Early morning and late afternoon	4500	230
UK Summer (!)	5500	180
Blue/white sky	6500	155
Light shade (summer) / overcast	7000	140
Typical shade (summer)	8000	125
Hazy sunlight	9000	110
Summer sky	30,000 +	33 -

Lens Filters: see Filters

Camera/projector speed/time: time taken till run out = footage/(3.75 x fps) minutes {35mm}

Camera/projector speed/time: time taken till run out = footage/(1.5 x fps) min. {16mm/super 16mm}

Projection: Sound displacement
format	Magnetic	Optical
70mm	-23 frames
35mm	-28 frames	+21 frames
16mm	+28 frames	+26 frames
Super 8	18 frames	22 frames
8mm	56 frames
Note: the film should be threaded one frame less for every 12 metres the viewer is from the speakers.

Shooting/playback length:

Format

8mm

(80 f/ft)

Super 8

(72 f/ft)

16mm

(40 frames/ft)

35mm

(16 f/ft)

All formats

Frames

fps

1sec

2.7"

3.6"

51/2"

71/2"

18"

18.75'

18f

24f

25f

1min

13ft

18ft

15'

20'

27'

36'

371/2'

90'

94'

1080

1440

1500

10min

135'

180'

150'

200'

270'

360'

375'

900'

937'

running time:
	8mm		Super 8		16mm			35mm
fps	18	24	18	24	18	24	*25fps*	*24fps*	25fps
100'	7'24	5'33	6'40	5'	3'42	2'46	2'40	1'6	64"
400'				20'	14'48	11'	10'40	4'26	4'16
1000'						27'40	26'40	11'6	10'40
1600'			106'	80'	59'16	44'27	n/a		n/a

Video tape formats
Format	Signal	LinearTape speed /sec	Head tape speed	Tape type	Tape width	Max recording	Typical user
VHS	A-Cmps	23.39mm	4.85m/s	Cb/chO₂	12.65mm	240 min	O c
SVHS	Y-C	23.39mm	4.85m/s	CbmO	12.65mm	180 min	CcON
Betacam	A-Cmpn	101.51m	5.75m/s	CbmO	12.65mm	110 min	News
Beta SP	A-Cmpn	101.51m	5.75m/s	Metal P	12.65mm	110 min	C B N
Digi Beta	Cmpn D 2:1 compression	96.7m	19.08m/s	Metal P	12.65mm	124 min	C B P
SX	Cmpn D	59.575mm	19.01m/s	Metal P	12.65mm	184 min	C N
D1	Cmpn D	286.9mm	35.34m/s	CbmO	19.01mm	94 min	P
D2	Cmps D	131.7mm	30.m/s	Metal P	19.01mm	208 min	B
D3	Cmps D	83.2mm	23.88m/s	Metal P	12.65mm	245 min	B N
D5	Cmpn D	167.2mm	n/a	Metal P	12.65mm	123 min	P
Digital-S	Cmpn D 4:2:2 1.6:1 compression	57.8mm	14.5m/s	Metal P	12.65mm	105 min	C B N
DV mini DV	Cmpn D 4:2:1 5:1 compression download	18.831mm	10.2m/s	Metal e	6.35 mm	270 min 63 min	C c N C c N
digital 8	Cmpn D				8 mm	60 min	c
DVCAM	Cmpn D 4:4:1 3.3:1 compression	28.246mm	10.2m/s	Metal e	6.35 mm	184 min	C N
DVCPRO	Cmpn D 4:2:2 3.3:1 compression	33.8mm	10.2m/s	Metal P	6.35 mm	123 min	C N
DVCPRO50	Cmpn D 4:2:2 1.6:1 compression						C B N
HDVcam & GR HD1 (JVC)	D (mpg4) 8:1 compression GR HD1 NTSC only				6.35 mm		c C
analogue high-definition	A (discontinued)
high-definition	1920x1080 24fps RGB

MII (M2)	A-Cmpn	66.295mm	5.9m/s	Metal P	12.65mm	97 min	C B
1 inch [10]	A-Cmps	239.8mm	21.39m/s	CbmO	25.4 mm	191 min	B Pedit
Hi-8	Y-C	20.05mm	8.54m/s	Metal P/e	8 mm	90 min	CcO N
Hi-band U-matic	A-Cmps	95.3mm	8.45m/s	CbmO	19 mm	60 min	C O N
SP Hi-Band U-matic	A-Cmps	95.3mm	8.45m/s	CbmO	19 mm	60 min	C O N
Lo-band U-matic	A-Cmps	95.3mm	8.45m/s	CbmO	19 mm	60 min	C O
Video 8	A-Cmps	20.05mm	3.18m/s	Metal P	8 mm	90 min	c
D-VHS	JVC/Sony next-generation VCR technology for the digital age. MPEG 2. 3 recording modes, based on a 420min tape HS, STD and LS. LS is split into four further catagories LS2...LS7. LS2 is DVD Quality & LS5 is VHS Quality. HS mode is used for HDTV signals. see JVC HM-DH30000 D-VHS Recorder
	recording time	Tape Speed	Net Data Rate			420min
D-VHS HS	3.5 hrs	33.33 mm/s	28.2 Mbps
D-VHS STD	7 hrs	16.67 mm/s	14.1 Mbps
D-VHS LS2	14 hrs	8.33 mm/s	7.0 Mbps
D-VHS LS3	21 hrs	5.67 mm/s	4.7 Mbps
D-VHS LS5	35 hrs	3.33 mm/s	2.8 Mbps
D-VHS LS7	49 hrs	2.38 mm/s	2.0 Mbps
DVD (is not a tape format!)	is considered 4:2:0, though actually 4:1:1 would be more correct. The difference between DVD and DV formats is that the chrominance sampling is subsampled vertically rather than horizontally. It's still important to have a 4:2:2 source though, because when you compress to DVD you compound the subsampling resulting in an even lower chroma resolution

Signal:: A = Analogue | Cmps = Composite.| Cmpn = Component.| D = Digital

Typical user:: c = consumer.| C = Corporate.| O = offline.| B = Broadcast.| N = news.| P = top-end post production.

Tape types: CbmO = Cobalt modified oxide.| ChO₂ = Chrome Dioxide.| Metal Particle | Metal evaporated.

[10] Obsolete reel to reel recorder. 1975-late 80's broadcast/archive standard, in use until advent of DigiBeta.

A simple qualative guide is (within a few %):
DVCPRO50=DigitalS
DVCPRO=DVCam=miniDV (mini/consumer DV is capable of same quality picture, however the lens, CCD and robustness of the tape will degrade the picture). All are better than BetaSP in tests, but subjectivly (and probably because of lenses and compression algorythm) sometimes appear worse. The 5:1 compression of these formats mean close-ups (talking heads) and moving images look good, often as good as DVCPRO50, DigitalS or better, however extremly detailed or complex scenes yield visibly, though not strongly, impaired video. Using the composite/Y-C output of these cameras will also degrade the picture (to BetaSP or worse) and so is not recomended to use composite/Y-C as an edit source if a digital output is avaliable.

There is a useful comparison of formats in May99 issue www.dv.com

physical tape dimensions:

In 1998 Film definition was approx 4 times that of standard TV and twice that of High definition TV.
More recently with film scanning techniques (shooting on film and DI, digital intermediate, for effects work a comparison is made grain size v scanning DPI (dots or pixels per inch, typically of an open gate 35mm image). Scanning is variously 1k, 2k or 4k although final projection is usually 2k or HD. Some tests have put recent (2004) Kodak (presumably slow) stocks at an equivalent of 6K. But you can't really compare static pixel locations with random film grain. Also random digital noise occurs in digital projectors, and this is akin to grain on film.

Computer Screen / Video resolutions and comparative film resolutions and aspect ratios
	Pixel ratio	Aspect ratio	Resolutions Aspect Ratio....
	(not square !)		1K	2K	4K
CGA (computer screen.....		3x4 = 1.33
VGA	640 x 480	1.33
SVGA	800 x 600	1.33
XGA	1024 x 768	1.33	approx here ?
SXGA	1365 x 1024	1.33	approx here ? [6]
DV -mini DV etc (video......	720 x 488	1.33 or 1.66 [3]
VCD ntsc (44.1kHz-mpeg1)	352 x 240	1.33
VCD pal (44.1kHz-mpeg1)	352 x 288	1.33
SuperVCD ntsc	480 x 480	1.33 or 1.66
SuperVCD pal (mpeg2)	480 x 576	1.33 or 1.66
Dvix (48khz audio mpeg4) [8]	640x480 [7]	any
GR HD1 (JVC) NTSC only		1.66
DVD		1.33 or 1.66
high-definition (HD)	1920 x 1080	1.66		approx here ?
D-1 (the standard for digital)	720 x 486	1.33
D-1 Standard Academy mask [1]	720 x 350
D-1 Standard Anamorphic mask [2]	720 x 274
Full Camera Aperture		1.33	1024x768	2048x1536	4096x3072 [4]
Academy Full Frame		1.37	914x666	1828x1332	3656x2664
Academy Projection		16x9 = 1.66	914x550	1828x1102 [5]	3656x2202
Academy Projection		1.85	914x494	1828x988	3656x1976
Anamorphic Pre-squeezed image		1.18	914x774	1828x1550	3656x3098
Un squeezed image		2.35	914x388	1828x778	3656x1556

[1] Using the D-1 standard of 720 x 486, Standard Academy Camera Aperture will utilize 720 x 350 of the avaliable 720 x 486.

[2] Anamorphic Camera Aperture (Cinemascope, Panavision, Widescreen) will only use 720 x 274

[3] The pixel ratio remains the same irrespective of aspect ratio.

[4] eg slow speed stock 35mm
[5] approx S16mm

[6] you can't really compare square pixels with random film grain of the same size, the latter is much less obtrusive
[7] (recommended)
[8] mpeg4 (Dvix) is a completly software compression system, ie requires a computer for playback and is dependent on the speed of processor. mpeg 1 and 2 have both software and hardware impliementations (including some standalone DVD players).

Download typical mini DV still picture

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Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
19°	27°	36°	50°	59°	63°	61°	54°	43°	31°	22°	17°